block: add bsg helper library

This moves the FC classes bsg code to the block layer and
makes it a lib so that other classes like iscsi and SAS can use it.

It is helpful because working with the request queue, bios,
creating scatterlists, etc are a pain that the LLD does not
have to worry about with normal IOs and should not have to
worry about for bsg requests.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0e67c45b3bc9..847928546076 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -30,6 +30,7 @@ struct request_pm_state;
 struct blk_trace;
 struct request;
 struct sg_io_hdr;
+struct bsg_job;
 
 #define BLKDEV_MIN_RQ   4
 #define BLKDEV_MAX_RQ   128     /* Default maximum */
@@ -209,6 +210,7 @@ typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
 typedef void (softirq_done_fn)(struct request *);
 typedef int (dma_drain_needed_fn)(struct request *);
 typedef int (lld_busy_fn) (struct request_queue *q);
+typedef int (bsg_job_fn) (struct bsg_job *);
 
 enum blk_eh_timer_return {
         BLK_EH_NOT_HANDLED,
@@ -375,6 +377,8 @@ struct request_queue {
         struct mutex            sysfs_lock;
 
 #if defined(CONFIG_BLK_DEV_BSG)
+        bsg_job_fn              *bsg_job_fn;
+        int                     bsg_job_size;
         struct bsg_class_device bsg_dev;
 #endif